The fascinating thing is that the stones are actually not very rare. But nevertheless, we still know very little about them. Research about Chameleon diamonds is only something of the past couple of years. But it also takes years before all  of the secrets of this rare green diamond come to the table. At this point, we consider the diamond as "a nice to have" and a collector's item for the enthusiast diamond collector.

What do we know about the stone's appearance?

Like the eponymous reptiles that change color by itself to adapt to their habitat, chameleon diamonds color themselves as well. Their color depends on the amount of light and the temperature of the environment. Under "normal" circumstances, the diamonds are green. But under other conditions, the color ranges from brown to bright yellow/orange. If the stone is in the dark for more than 24 hours or heated to 200 gr C, they are bright yellow/orange. But this change in color is never permanent. As the stones cool down or catch the light, they get back to their original olive color. Usually within ten minutes.

What causes the discoloration?

Researchers still cannot explain where this behavior, called  thermochromism, comes from. What we do know is that these stones have high levels of hydrogen and traces of nickel and nitrogen in the crystal lattice. This combination probably causes the changes in color, the uplighting- and the fluorescent properties of the Chameleon diamond.

When are chameleon diamonds from?

In 1943, the Gemological Institute of America started the investigation to the properties of these stones. Before that, people just assumed they were green diamonds. Several specialists associated with the GIA conducted a series of experiments. They tested 29 diamonds to determine the differences between the typical green stone and chameleons. One of the researchers found that a regular green diamond permanently changes color when exposed to extreme heat. But chameleon diamonds always return to the original hue.

Well-known stones

There are some famous stones that have these chameleon qualities. One of them is the greatest chameleon ever discovered and treated. This is the 31.32 carat Chopard Chameleon. Another famous and beautiful stone of 8.8 carats was auctioned a few years ago at Christy's. It raised $ 590,000. There was also an auction of a 4-carat chameleon that went for $ 240,000. But one of these diamonds really stood out. A "small" 8.08-carat stone that was estimated by GIA on a value of $ 2,100,000. Chopard Chameleon diamond - source: chopard.com

Colored diamonds

At Royal Coster Diamonds, we are amazed by rare diamond gifts from nature like Chameleon Diamond. Think for example about tanzanite, sapphires and black diamonds. This is why we have some amazing collections of colored stones. See this collection for yourself during a tour through our diamond polishing factory or contact a diamond consultant.